The invention relates to a zig-zag folded web of paper material in particular for further processing as dunnage material or cushioning material for example by means of a dunnage material machine which mechanically forms a folded paper web into a dunnage material, such as a cushioning material, particularly without adding any further materials to the paper web.
One example for a zig-zag folded stack of paper web for producing the dunnage material stack and a dunnage material machine suitable therefore are known from EP 1 345 757 B1, wherein reference is particularly made to FIG. 3 of EP 1 345 757 B1 which shows the zig-zag folded stack of paper web.
In order to increase the stacking height and the folding capability of the paper web, it is known to perforate the folds of the stack of paper web whereby the web of material is weakened in order to predetermine the run of the fold(s) of the web paper material in an accurately positioned manner, to decrease the space of the fold(s) and in order to enable the later tearing off of the material web having been formed into a dunnage material.
It is known to form the folds of the zig-zag folded stack of paper web with a perforation-tie-row or row of perforations and ties. One example for a known perforated fold shall be schematically illustrated with the attached FIG. 1. The perforation-tie-row (e) is continuously formed with a tie-width and perforation-width remaining constant along the entire longitudinal extension in the longitudinal direction of the fold q lying parallel to the crosswise direction of the paper web. The ratio perforation-width to tie-width lies at 2:1 or 3:1 in favor of a larger perforation-width. It is known that the fold-tie (b), i.e. the bridge comprises its maximal longitudinal extension (xi) along the fold (a) in the longitudinal fold direction (q) of at most 1 mm. The perforation (c), that is the oblong or an elongated hole or through hole, is formed in the paper web with a maximal longitudinal extension (y′) of 2 mm to 3 mm.
It has been shown that, in particular when utilizing a folded stack of paper web made of short-fiber paper material, when unfolding and during feeding conveyance into the dunnage machine, the paper web tears apart along the weakened fold or crease so that the automized production process for dunnage material is disturbed. Most of all when increasing the feeding velocity of the paper web into the dunnage material machine, the unfolding forces increase so much that an unfolding of the stack of paper web free of tearing can no longer be ensured with sufficient reliability.
It is an objective of the invention to overcome the disadvantages of the prior art, particularly to provide a zig-zag folded for fan-folded stack of paper web particularly made of recycling paper, preferably on the basis of 100% used paper, wherein on one hand folding in a positionally predefined and space-saving manner is simplified, and on the other hand unintentional tearing apart of the paper web particularly during machine-processing into dunnage material it is avoided, wherein in particular a simple, positionally accurate tearing of the dunnage material made from the stack of paper web is simplified.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.